backup withholding
noun[U]
ukusTAX
in the US, asystemin which thetaxon theincomefrom sometypesofinvestmentissentdirectlyto thetaxauthority, forexamplewhen abankdoes not have all theinformationitneedsabout thepersonpayingthetax:
Under thebackupwithholdingrules, thebusinessorbankmustwithholdon apaymentif thepayeedid notprovideataxpayeridentificationnumber.